North America Native Plant

King’s Ragwort

Botanical name: Senecio eremophilus var. kingii

USDA symbol: SEERK

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Synonyms: Senecio ambrosioides Rydb. (SEAM3)  âš˜  Senecio eremophilus Richardson ssp. kingii (Rydb.) G.W. Douglas & G. Ruyle-Douglas (SEERK2)  âš˜  Senecio kingii Rydb. (SEKI)   

King’s Ragwort: A Lesser-Known Native Wildflower for Specialized Gardens If you’re the type of gardener who loves to dig deep into the world of native plants, you might have stumbled across King’s ragwort (Senecio eremophilus var. kingii). This perennial wildflower is one of those plants that makes botanists get excited ...

King’s Ragwort: A Lesser-Known Native Wildflower for Specialized Gardens

If you’re the type of gardener who loves to dig deep into the world of native plants, you might have stumbled across King’s ragwort (Senecio eremophilus var. kingii). This perennial wildflower is one of those plants that makes botanists get excited but leaves most gardeners scratching their heads. Let’s explore what makes this native plant special and whether it deserves a spot in your garden.

What Exactly is King’s Ragwort?

King’s ragwort is a native perennial forb that belongs to the sunflower family. As a forb, it’s essentially a wildflower – a non-woody plant that dies back to the ground each winter and returns from its roots in spring. You might also see it listed under several scientific synonyms, including Senecio kingii or Senecio ambrosioides, which can make tracking down information about this plant quite the treasure hunt.

Where Does It Call Home?

This native beauty has made itself at home across the western United States, specifically in Arizona, Colorado, New Mexico, Utah, and Wyoming. It’s perfectly adapted to the challenging conditions of these regions, making it a true survivor of the American West.

Should You Grow King’s Ragwort?

Here’s where things get a bit tricky. While King’s ragwort is undoubtedly a legitimate native plant, it’s also what we might call a specialist species. This means it has very specific growing requirements that aren’t well-documented in typical gardening resources. For most home gardeners, this presents both an opportunity and a challenge.

The honest truth? Unless you’re a dedicated native plant enthusiast with experience growing challenging species, you might want to consider some easier alternatives first. There are many other Senecio species and western wildflowers that offer similar ecological benefits with more available growing information.

The Growing Challenge

Unfortunately, detailed growing information for this specific variety is quite limited. What we do know is that as a western native adapted to diverse conditions across five states, it likely prefers:

  • Well-draining soils (most western natives do)
  • Full sun to partial shade
  • Minimal supplemental watering once established
  • Cool to cold winter conditions for proper dormancy

However, without specific data on soil pH preferences, exact water requirements, or detailed care instructions, growing this plant becomes somewhat experimental.

A Better Approach for Most Gardeners

If you’re interested in supporting native pollinators and wildlife in western regions, consider starting with better-documented native alternatives such as:

  • Purple prairie clover (Dalea purpurea)
  • Rocky Mountain penstemon (Penstemon strictus)
  • Blanket flower (Gaillardia aristata)
  • Other well-studied Senecio species native to your specific area

These alternatives offer similar ecological benefits with much more available growing guidance.

For the Adventurous Gardener

If you’re determined to try King’s ragwort, here are some general tips for success with challenging native species:

  • Source seeds or plants only from reputable native plant nurseries
  • Try growing it in a dedicated native plant area first
  • Mimic the natural conditions of its native range
  • Be patient – specialized natives often take time to establish
  • Connect with local native plant societies for region-specific advice

The Bottom Line

King’s ragwort represents the fascinating diversity of our native plant communities, but it’s definitely not a beginner-friendly choice. While we can appreciate its role in natural ecosystems, most gardeners will find greater success and satisfaction with better-documented native alternatives that offer similar ecological benefits.

Remember, the best native plant for your garden is one you can actually grow successfully. Start with the tried-and-true natives, master those, and then perhaps venture into the more mysterious species like King’s ragwort once you’ve built your confidence and expertise.

King’s Ragwort

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Asterales

Family

Asteraceae Bercht. & J. Presl - Aster family

Genus

Senecio L. - ragwort

Species

Senecio eremophilus Richardson - desert ragwort

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA